Book light question

I've recently learned what a book light/wedge light is but have not seen it in action, nor have I had to set one up. I would like to know what circumstances call for this type of lighting, what else can you use to have a similar effect.

A booklight is essentially just a very soft source, being a bounced source which is then diffused. You would use them any time you need a super soft source. They are tremendously power inefficient. A similar technique would be Double diffusing a lamp by putting it through 2 separate frames

A booklight is essentially just a very soft source, being a bounced source which is then diffused. You would use them any time you need a super soft source. They are tremendously power inefficient. A similar technique would be Double diffusing a lamp by putting it through 2 separate frames